Category Archives: Gastropods

Sinployea aunuuana Solem

Aunuu Sinployea Snail (Sinployea aunuuana)

This species, which is restricted to the small island of ‘Aunu’u offshore Tutuila’s east coast in the American part of Samoa, was described in the year 1983.

The shell reaches an average size of 0,28 cm in diameter. [1]

~~~

The island of ‘Aunu’u was investigated in intensive field studies in the year 2001, when the island was found to be infested with two alien snail species: the Two-toned Gulella (Huttonella bicolor (Hutton)), and the West African Streptostele Snail (Streptostele musaecola (Morelet)); both are known to be invasive, mainly snail-eating species, and both are found on many Pacific islands now.

The Aunuu Sinployea Snail was not found in 2001, and is now considered most likely extinct. [2]

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References:

[1] Alan Solem: Endodontoid land snails from Pacific Islands (Mollusca: Pulmonata: Sigmurethra). Part II, Families Punctidae and Charopidae, Zoogeography. Field Museum of Natural History Chicago, Illinois 1983
[2] Robert H. Cowie; Rebecca J. Rundell: The Land Snails of a small tropical island, Aunu’u, American Samoa. Pacific Science 56(2): 143-147. 2002

Powelliphanta augusta Walker, Trewick & Barker

Mount Augustus Predatory Snail (Powelliphanta augusta)

This species was described in 2008, it was until then known under the tag name Powelliphanta “Augustus”. [1]

The Mount Augustus Predatory Snail was discovered in 1996 at the ridgeline of Mt. Augustus northeast of Westport.

This locality was subsequently destroyed by mining operations, and about 6000 snails were taken from the locality in 2007 to protect them from the mine development. The ca. 4000 snails that were released to nearby sites showed an alarmingly high mortality rate, and 800 were even killed accidently by the Department of Conservation in a fridge during a captive program in 2011.

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References:

[1] Steven A. Trewick; Kath J. Walker; Corina J. Jordan: Taxonomic and conservation status of a newly discovered giant landsnail from Mount Augustus, New Zealand. Conservation Genetics 9(6): 1563-1575. 2008

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Photo: K. J. Walker

(under creative commons license (4.0))
http://creativecommons.org/licenses/by/4.0

Orobophana musiva (Gould)

Mosaic Orobophana Snail (Orobophana musiva)

This species was described in 1847, it is found in Fiji, in Samoa, and obviously in Tuvalu as well.

The Mosaic Orobophana Snail is found under decaying vegetation at low elevations, very often near the coast.

It is a very small species, the shells reach heights of only about 0,2 cm, they vary in color from several shades of yellow and orange to reddish-brown.

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References:

[1] Robert H. Cowie; Rebecca J. Rundell: The land snails of a small tropical island, Aunu’u, American Samoa. Pacific Science 56(2): 143-147. 2002

Ostodes exasperatus Girardi

Large Ostodes Snail (Ostodes exasperatus)

This species was described in 1978.

The species is known from the islands of Savai’i and ‘Upolu, however, these two populations differ from each other in so far that the males from ‘Upolu are larger than the females, while the situation is reversed in Savai’i.

The shells reach a height of about 0,9 to 1,3 cm and a width of up to 1,3 cm. [1][2]

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References:

[1] E. L. Girardi: The Samoan land snail genus Ostodes (Mollusca: Prosobranchia: Poteriidae). The Veliger 20(3): 191-246. 1978
[2] Robert H. Cowie: Catalog of the nonmarine snails and slugs of the Samoan Islands. Bishop Museum Bulletin in Zoology 3. 1998

Powelliphanta spedeni (Powell)

Speden’s Predatory Snail (Powelliphanta spedeni)

This species, described in 1932, is endemic to the South Island of New Zealand.

The shell reaches a size of about 4 cm in diameter.

This species is thought to contain two subspecies, the nominate, Powelliphanta spedeni ssp. spedeni (Powell), and Powelliphanta spedeni ssp. lateumbilicata (Powell).

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Powelliphanta spedeni ssp. lateumbilicata

Photo: D. Coetzee

(public domain)

Minidonta extraria Cooke & Solem

Strange Disc Snail (Minidonta extraria)

This species was described in the year 1976 from three specimens, of which one was found on the island of Akamaru, one on the island of Mangareva, and one on the island of Taravai.

The shells reach an average size of 0,29 cm in diameter.

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References:

[1] Alan Solem: Endodontoid land snails from Pacific Islands (Mollusca: Pulmonata: Sigmurethra). Part I, Family Endodontidae. Field Museum of Natural History Chicago, Illinois 1976
[2] Ahmed Abdou; Philippe Bouchet: Nouveaux gastéropodes Endodontidae et Punctidae (Mollusca, Pulmonata) récemment éteints da l’archipel des Gambier (Polynésie). Zoosystema 22(4): 689-707. 2000

Justin Gerlach: Partula – Icons of Evolution

Justin Gerlach: Partula – Icons of Evolution

The genus Partula, extremely rich in Polynesian species, will soon get it’s newest monograph (I’m not sure, but it may be the first monograph at all).

The book, written by Justin Gerlach and named “Partula – Icons of Evolution”, is nearly ready to be published, but the project can still be supported.:

https://www.kickstarter.com/projects/507116283/partula-icons-of-evolution

 

Endodonta apiculata Ancey

Pointed Disc Snail (Endodonta apiculata)

The Pointed Disc Snail, which was restricted to the island of Kaua’i, Hawaiian Islands, was described in the year 1889.

The shells of this species reached an average size of 0,6 cm in diameter. [1]

~~~

The genus Endodonta contains a little more than 10 species, all, except probably for one, are now obviously extinct.

The destruction of large areas of the native lowland habitats led to their extinction, and introduced invasive species, especially several aggressive ant species (for example the Red Fire Ant (Solenopsis invicta Buren) or the Little Fire Ant (Wasmannia auropunctata (Roger))) are a very serious threat to the last remaining endemic snail species, and are blamed for the extinction of many island endemic species. [2]

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References:

[1] Alan Solem: Endodontoid land snails from Pacific Islands (Mollusca: Pulmonata: Sigmurethra). Part I, Family Endodontidae. Field Museum of Natural History Chicago, Illinois 1976
[2] Norine W. Yeung; Kenneth A. Hayes: Update on the status of the remaining Hawaiian land snail species Part 4: Punctidae and Endodontidae. 2016

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edited: 23.03.2017

Partula otaheitana (Bruguière)

Otaheite Tree Snail (Partula otaheitana)

The Otaheite Tree-Snail, whose name refers to it as being endemic to the island of Tahiti (Otaheite is an old name of the island), was described in 1792.

This species is nowadays highly threatened with extinction, yet somehow managed to withstand the introduction of the Rosy Wolf Snail (Euglandia rosea (Férussac)) to Polynesia, that had cost the lives of so many other endemic snail species.

~~~

The Otaheite Tree-Snail is split into four so called anatomical forms, which overlap or are linked to each other by intermediate forms, and which are each restricted to certain parts of Tahiti. They may or may not be treated as subspecies, and are named as Partula otaheitana ssp. crassa Garrett (in the western part of Tahiti nui), Partula otaheitana ssp. otaheitana Bruguière (in the northern part of Tahiti nui), Partula otaheitana ssp. rubescens Reeve (in the eastern part of Tahiti nui as well the northern part of Tahiti iti), and finally Partula otaheitana ssp. sinistrorsa Garrett (in the largest part of Tahiti nui, including the center of the island and the southern part, as well as the most parts of Tahiti iti).

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References:

[1] Justin Gerlach: Icons of Evolution: Pacific Island tree-snails, family Partulida, Phelsuma Press, Cambridge U.K. 2016

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Photo: Antonio Machado; by courtesy of Antonio Machado

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edited: 31.08.2017

Anceyodonta andersoni Cooke & Solem

Anderson’s Disc Snail (Anceyodonta andersoni)

Anderson’s Disc Snail was described in the year 1976.

The species was originally known only based on specimens that had been collected in 1934 on the island of Mangareva, but was subsequently (in 2000) recorded in form of subfossil shells from Taravai, Mangareva’s neighbor island, as well.

The shells of the species reached an average size of 0,29 to 0,36 cm in diameter.

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References:

[1] Alan Solem: Endodontoid land snails from Pacific Islands (Mollusca: Pulmonata: Sigmurethra). Part I, Family Endodontidae. Field Museum of Natural History Chicago, Illinois 1976
[2] Ahmed Abdou; Philippe Bouchet: Nouveaux gastéropodes Endodontidae et Punctidae (Mollusca, Pulmonata) récemment éteints da l’archipel des Gambier (Polynésie). Zoosystema 22(4): 689-707. 2000

Powelliphanta marchanti (Powell)

Marchant’s Predatory Snail (Powelliphanta marchanti)

This species is restricted to the western Ruahine Ranges on the North Island of New Zealand, where it can be found amongst leaf litter in native forest.

Like its congeners, also this is a carnivorous species that feeds upon invertebrates, preferably on earthworms.

~~~

Marchant’s Predatory Snail is in decline and highly endangered.

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Photo: V. Vercoe

(under creative commons license (4.0))
http://creativecommons.org/licenses/by/4.0

Partula lutea (Lesson)

Yellow Tree Snail (Partula lutea)

This variably colored species was described in the year 1831.

The species was endemic to the island of Bora Bora, Society Islands, where it was the only member of its genus, and where it was still numerously found in the 19th century on the stems, branches, and leaves of the native vegetation.

The shells reached a height of nearly 2 cm and was usually pale yellowish to light brown with the apex being of the same color or slightly darker.

The Yellow Tree-Snail is now extinct. [1]

~~~

The same species was introduced to the island of Maupiti sometimes after 1929, from where it is known, however, only from subfossil shells, found and photographed in 2010, 2012 and 2017 by J.-F. Butaud, J. Gerlach and others.

The species is extinct on Maupiti as well. [1][2]

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References:

[1] Justin Gerlach: Icons of Evolution: Pacific Island tree-snails, family Partulida, Phelsuma Press, Cambridge U.K. 2016
[2] Justin Gerlach: Partula survival in 2017, a survey of the Society Islands

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Depiction from: ‘George W. Tryon; Henry A. Pilsbry; u.a.: Manual of Conchology. Second Series: Pulmonata Vol. 20, Caecilioides, Clessula and Partulidae. Index to Vols. 16-20. 1909-1910’

(public domain)

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edited: 31.08.2017

Septaria suffreni (Récluz)

Samoan Limpet Snail (Septaria suffreni)

Distribution:

Fiji: Kadavu, Ovalau, Taveuni, Vanua Levu, Viti Levu
Samoa

local names: –

***

This species occurs from New Caledonia and Vanuatu, Melanesia to Fiji and Samoa in the westernmost Polynesia, where it inhabits tidal regions of rivers and streams but can also be found well inland.

The Samoan Limpet Snail is the most common member of its genus in the rivers of Samoa.

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References:

[1] A. Haynes: A revision of the genus Septaria Férussac, 1803 (Gastropoda: Neritimorpha) Annalen des Naturhisorischen Museums Wien 103 B: 177-229. 2001

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Photo: S. Hashizume, 2008
http://jocv183199.web.fc2.com

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edited: 22.12.2018

Nesoropupa fenua Gargominy

Fenua Whorl Snail (Nesoropupa fenua)

Distribution:

Society Islands: Tahiti

local names: –

***

The Fenua Whorl Snail, described in 2008, is known exclusively from its type location, the very summit of Mt. Aorai on the island of Tahiti, Society Islands, it is known so far only from three empty shells that were collected from the leaf litter.

The species is very likely arboreal like its three known congenerics.

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References:

[1] Olivier Gargominy: Beyond the alien invasion: A recently discovered radiation of Nesopupinae (Gastropoda: Pulmonata: Vertiginidae) from the summits of Tahiti (Society Islands, French Polynesia). Journal of Conchology 39(5): 517-536. 2008

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edited: 15.12.2018

Mautodontha consobrina (Garrett)

Huahine Mautodontha Snail (Mautodontha consobrina)

This species, which comes from the island of Huahine, was described in the year 1884.

The shells reach an average size of 0,38 cm in diameter.

Andrew J. Garrett, the species’ author writes in the year 1884.:

Rare and peculiar to one valley.

This statement is all, that is known about this now extinct species, of which obviously only seven museum specimens are in existence.

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References:

[1] Andrew J. Garrett: The terrestrial Mollusca inhabiting the Society Islands”. Journal of the Academy of Natural Sciences of Philadelphia. 2nd series 9: 17-114. 1884
[2] Alan Solem: Endodontoid land snails from Pacific Islands (Mollusca: Pulmonata: Sigmurethra). Part I, Family Endodontidae. Field Museum of Natural History Chicago, Illinois 1976

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mautodontha-consobrina-mc

Depiction from: ‘G. W. Tryon; H. A. Pilsbry; u.a.: Manual of Conchology. Second Series: Pulmonata Vol. 3, Helicidae Vol. 1. 1887’

http://www.biodiversitylibrary.org

Partula fusca Pease

Brown Tree-Snail (Partula fusca)

The Brown Tree-Snail, whose shells were not always brown colored, but were as variable as the shells of most tree-snails, was endemic to the island of Ra’iatea.

The species was obviously not a tree dweller but terrestrial.

The Brown Tree-Snail, like most of its relatives from the island of Ra’iatea, died out at the end of the 20th century.

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partula-fusca-mc

Depiction from: ‘George W. Tryon; Henry A. Pilsbry; u.a.: Manual of Conchology. Second Series: Pulmonata Vol. 20, Caecilioides, Clessula and Partulidae. Index to Vols. 16-20. 1909-1910’

http://www.biodiversitylibrary.org

Partula auriculata Broderip

Ear-shaped Tree-Snail (Partula auriculata)

This species was decsribed in the year 1832.

The Ear-shaped Tree-Snail was an endemic species of the island of Ra’iatea and disappeared shortly after the introduction of the Rosy Wolfsnail (Euglandina rosea (Férussac)) to the island. In the year 1992, when the species was seen for the last time, only a few individuals were left.

The species was not found during field surveys in the years 1994 and 2000, nor during any other subsequent survey, and therefore is considered extinct now.

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partula-auriculata-mc

Depiction from: ‘George W. Tryon; Henry A. Pilsbry; u.a.: Manual of Conchology. Second Series: Pulmonata Vol. 20, Caecilioides, Clessula and Partulidae. Index to Vols. 16-20. 1909-1910’

http://www.biodiversitylibrary.org

Minidonta aroa Brook

Aroa Minidonta Snail (Minidonta aroa)

This species was described in the year 2010 from subfossil shells that were found in the sandy soil of the coastal plains between the villages of Aro’a and Arorangi on the southwest coast of the island of Rarotonga.

The shells reach an average size of 0,25 to 0,3 cm in diameter.

~~~

The species, which obviously was restricted to lowland areas, died out most probably already shortly after the colonization of the island by Polynesians.

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References:

[1] F. J. Brook: Coastal landsnail fauna of Rarotonga, Cook Islands: systematics, diversity, biogeography, faunal history, and environmental influences. Tuhinga 21: 161-252. 2010

Anceyodonta ganhutuensis Cooke & Solem

Gahutu Disc Snail (Anceyodonta ganhutuensis)

The Gahutu Disc Snail was described in the year 1976 based on subfossil shells, which had been found near the Gahutu Bay (not Ganhutu!) on the island of Mangareva, shells of this species were subsequently found on the island of Taravai as well.

The shells of this species reach an average size of 0,17 to 0,22 cm in diameter.

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References:

[1] Alan Solem: Endodontoid land snails from Pacific Islands (Mollusca: Pulmonata: Sigmurethra). Part I, Family Endodontidae. Field Museum of Natural History Chicago, Illinois 1976
[2] Ahmed Abdou; Philippe Bouchet: Nouveaux gastéropodes Endodontidae et Punctidae (Mollusca, Pulmonata) récemment éteints da l’archipel des Gambier (Polynésie). Zoosystema 22(4): 689-707. 2000

Sinployea clista Solem

Closed Sinployea Snail (Sinployea clista)

This species was described in the year 1983.

The ‘species’ occurs on the islands of Tutuila and ‘Upolu, the respective populations, however, differ from each other, and with certainty represent at least distinct subspecies, or possibly even species.

The shells reach sizes of about 0,21 to 0,29 cm in diameter. [1]

~~~

The population of the island of ‘Upolu was not found again during field searches in the years from 1992 to 1994, and is now most probably wiped out. [2]

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References:

[1] Alan Solem: Endodontoid land snails from Pacific Islands (Mollusca: Pulmonata: Sigmurethra). Part II, Families Punctidae and Charopidae, Zoogeography. Field Museum of Natural History Chicago, Illinois 1983
[2] Robert H. Cowie; A. C. Robinson: The decline of native Pacific island faunas: changes in status of the land snails of Samoa through the 20th century. Biological Conservation 110: 55-65. 2003

Taipidon octolamellata (Garrett)

Eight-grooved Taipidion Snail (Taipidon octolamellata)

This species comes from the island of Hiva Oa, it was described in the year 1887, and obviously died out shortly after.

~~~

Obviously, there is only a single voucher specimen left today, a shell with a size of about 0,4 cm in diameter.

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References:

[1] Alan Solem: Endodontoid land snails from Pacific Islands (Mollusca: Pulmonata: Sigmurethra). Part II, Families Punctidae and Charopidae, Zoogeography. Field Museum of Natural History Chicago, Illinois 1983

Minidonta matavera Brook

Matavera Minidonta Snail (Minidonta matavera)

The Matavera Minidonta Snail from the island of Rarotonga was described in the year 2010.

This species is known only from empty shells, some of which are in a subfossil condition, while others appear relatively fresh, suggesting a relatively recent extinction date.

The shells reached a height of about 0,25 cm. [1]

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References:

[1] Fred J. Brook: Coastal landsnail fauna of Rarotonga, Cook Islands: systematics, diversity, biogeography, faunal history, and environmental influences. Tuhinga 21: 161-252. 2010

Anceyodonta gatavakensis Abdou & Bouchet

Gatavake Disc Snail (Anceyodonta gatavakensis)

This species was described in the year 2000.

The Gatavake Disc Snail is known only from subfossil shells, which hed been found near the village of Gatavake at the northwest coast of the island of Mangareva.

The somewhat dome-shaped shells reached an average size of 0,22 cm in diameter. [1]

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References:

[1] Ahmed Abdou; Philippe Bouchet: Nouveaux gastéropodes Endodontidae et Punctidae (Mollusca, Pulmonata) récemment éteints da l’archipel des Gambier (Polynésie). Zoosystema 22(4): 689-707. 2000

Fluviopupa tubuaia Haase, Gargominy & Fontaine

Tubuai Freshwater Snail (Fluviopupa tubuaia)

This species from the island of Tubuai was scientifically described in the year 2005.

The species occurs, as far as known, on only a single place, a small stream southeast of Mont Taitaa, it is therefore considered highly threatened.

The shell reaches a height of about 0,3 cm and is, as in all other species of this genus, translucent brown in color.

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References:

[1] M. Haase; O. Gargominy; B. Fontaine: Rissooidean freshwater gastropods from the middle of the Pacific: the genus Fluviopupa on the Austral Islands (Caenogastropoda). Molluscan Research 25(3): 145-163. 2005

Thaumatodon decemplicata (Mousson)

Tuvaluan Thaumatodon Snail (Thaumatodon decemplicata)

This species was described in the year 1873.

The minute species, whose shell reaches a size of only about 0,26 cm in diameter, seems to live in decaying wood.

The Tuvaluan Thaumatodon Snail is currently known only from several specimens that had been collected on the Nukufetau- and the Vaitupu atoll respectively, its status is unfortunately currently unknown.

~~~

The genus Thaumatodon currently comprises nine species, which all occur exclusively on some few islands in Polynesia.

Samoana jackieburchi Kondo

Jackie Burch’s Samoana Tree-Snail (Samoana jackieburchi)

This species was described in the year 1980 and is considered extinct since.

The Rosy Wolfsnail (Euglandina rosea (Férussac)), which was introduced to Tahiti in 1977, is blamed for the extinction of this and several other snail species.

The shells of this species are exclusively sinistral (twisted leftward).

~~~

Jackie Burch’s Samoana Tree-Snail, whose taxonomy is somewhat disputed, appears superficially almost identical to a specific subspecies of the Tahitian Tree-Snail, the Reddish Tahitian Tree-Snail (Partula otaheitana ssp. rubescens Reeve), and thus is sometimes (incorrectly) synonymized with it.

~~~

Another species from the island of Tahiti that was also believed to be extinct , Burch’s Samoana Tree-Snail (Samoana burchi Kondo), was rediscovered in the year 2005 (?).

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References:

[1] Y. Kondo: Samoana jackieburchi, new species (Gastropoda: Pulmonata: Partulidae). Malacological Review 2: 25-32. 1980
[2] Trevor Coote: Pacific Island Land Snails; Tahiti becomes the focus of Partula conservation. Tentacle 20: 28-30. 2012

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edited: 05.10.2016

Partula cuneata Crampton

Wedge-shaped Tree-Snail (Partula cuneata)

The Wedge-shaped Tree-Snail was described in the year 1956.

The species was endemic to the island of Ra’iatea, where it was restricted to the Ereeo Valley on the west coast of the island, which it shared with five additional tree-snail species – all of these species are now extinct.

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References:

[1] Henry E. Crampton: New Species of Land Snails of the Genus Partula from Raiatea, Society Islands. American Museum Novitates 1761: 1-17. 1956

Mautodontha maupiensis (Garrett)

Maupiti Disc Snail (Mautodontha maupiensis)

This species from the island of Maupiti was described in the year 1884.

The shells reach an average size of 0,3 cm in diameter. [2]

~~~

Andrew J. Garrett, the species’ author, writes in the year 1884.:

“Very common, and confined to the small island of Maupiti.”

Thus, the Maupiti Disc Snail, of which today twenty-one museum specimens are still in existence, must still have been very common in the 19th century, but died out shortly after. [1][2]

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References:

[1] Andrew J. Garrett: The terrestrial Mollusca inhabiting the Society Islands”. Journal of the Academy of Natural Sciences of Philadelphia. 2nd series 9: 17-114. 1884
[2] Alan Solem: Endodontoid land snails from Pacific Islands (Mollusca: Pulmonata: Sigmurethra). Part I, Family Endodontidae. Field Museum of Natural History Chicago, Illinois 1976

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mautodontha.maupiensis.mc

Depiction from: ‘G. W. Tryon; H. A. Pilsbry; u.a.: Manual of Conchology. Second Series: Pulmonata Vol. 3, Helicidae Vol. 1. 1887’

http://www.biodiversitylibrary.org

Graeffedon graeffei (Mousson)

Gräffe’s Graeffedon Snail (Graeffedon graeffei)

This species from the Samoan island of ‘Upolu, which is known only from a handful specimens, was described in the year 1869.

The shells reach an average size of 0,46 to 0,59 cm in diameter.

Gräffe’s Graeffedon Snail inhabited the leaf litter of the rainforests, where it easily felt victim to introduced rats, and more so to the likewise introduced Yellow Crazy Ants (Anoplolepis gracilipes F. Smith).

The last specimen was collected in the year 1965.

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References:
[1] Alan Solem: Endodontoid land snails from Pacific Islands (Mollusca: Pulmonata: Sigmurethra). Part II, Families Punctidae and Charopidae, Zoogeography. Field Museum of Natural History Chicago, Illinois 1983
[2] Robert H. Cowie; A. C. Robinson: The decline of native Pacific island faunas: changes in status of the land snails of Samoa through the 20th century. Biological Conservation 110: 55-65. 2003

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graeffedon-graeffei-mc

Depiction from: ”G. W. Tryon; H. A. Pilsbry; u.a.: Manual of Conchology. Second Series: Pulmonata Vol. 3, Helicidae Vol. 1. 1887′

http://www.biodiversitylibrary.org

Anceyodonta alternata Cooke & Solem

Mangarevan Disc Snail (Anceyodonta alternata)

This species was described in the year 1976 from shells that were collected in the north part of Rikitea, the main settlement on the island of Mangareva.

The shells reach an average size of about 0,22 cm in diameter.

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References:

[1] Alan Solem: Endodontoid land snails from Pacific Islands (Mollusca: Pulmonata: Sigmurethra). Part I, Family Endodontidae. Field Museum of Natural History Chicago, Illinois 1976
[2] Ahmed Abdou; Philippe Bouchet: Nouveaux gastéropodes Endodontidae et Punctidae (Mollusca, Pulmonata) récemment éteints da l’archipel des Gambier (Polynésie). Zoosystema 22(4): 689-707. 2000

Minidonta iota Brook

Dwarfed Minidonta Snail (Minidonta iota)

This species was described in the year 2010 from very few, badly preserved subfossil shells, which were found in the sandy soil of the coastal plain near the village of Aro’a on the southwest coast of the island of Rarotonga.

The shells of this species reached an average size of 0,13 to 0,15 cm in diameter, which makes it the smallest of all known Endodontidae species at all.

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References:

[1] Fred J. Brook: Coastal landsnail fauna of Rarotonga, Cook Islands: systematics, diversity, biogeography, faunal history, and environmental influences. Tuhinga 21: 161-252. 2010

Atropis rarotongana Brook

Rarotongan Atropis Snail (Atropis rarotongana)

This species was described in the year 2010 on the basis of subfossil shells, which were found in the years 2005 to 2007 on several beach areas on the island of Rarotonga.

Some of these shells, which were found in the coral rubble at the ground of a small grove of Fish Poison Trees (Barringtonia asiatica (L.) Kurz) at Matavera in the east part of the island, where empty but, however, appeared relatively fresh, and the author (Fred J. Brook) in its species description assumes that this species may have survived at least until this time (2005 – 2007).

Because of the omnipresent rats (three species occur on Rarotonga: Rattus exulans (Peale), Rattus norvegicus (Berkenhout), Rattus rattus (L.)), a survival of this species, however, is very unlikely.

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References:

[1] Fred J. Brook: Coastal landsnail fauna of Rarotonga, Cook Islands: systematics, diversity, biogeography, faunal history, and environmental influences. Tuhinga 21: 161-252. 2010

Aukena tridentata (B. Baker)

Three-toothed Aukena Hive Snail (Aukena tridentata)

The Three-toothed Aukena Hive Snail was described in the year 1940 based on empty shells that had been collected in the year 1934 during the ‘Mangarevan Expedition’ on the islands of Aukena and Mangareva.

The shells reach an average size of 0,55 cm in diameter.

The shells were found in the sandy soil of small coastal plains, that are now completely modified for small-scale agriculture. [1][2]

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References:

[1] H. Burrington Baker: Zonitid snails from Pacific Islands: Hawaiian genera of Microcystinae. Bishop Museum Bulletins 165 : 105-201. 1940
[2] Philippe Bouchet; Ahmed Abdou: Recent Extinct Land Snails (Euconulidae) from the Gambier Islands with Remarkable Apertural Barriers. Pacific Science 55(2): 121-127. 2001

Partula rustica Pease

Rustic Tree-Snail (Partula rustica)

This species comes from the island of Ra’iatea, and was obviously restricted to a single valley at the west coast of the island, where the animals were found under decaying plant material.

The Rustic Raiatea Tree-Snail is now, like most of its relatives from the island of Ra’iatea, considered extirpated.

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partula-rustica-mc

Depiction from: ‘George W. Tryon; Henry A. Pilsbry; u.a.: Manual of Conchology. Second Series: Pulmonata Vol. 20, Caecilioides, Clessula and Partulidae. Index to Vols. 16-20. 1909-1910’

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Diastole schmeltziana (Mousson)

Samoan Diastole Snail (Diastole schmeltziana)

This very variable species, which was described in the year 1865, occurs on all of the Samoan islands and seems to be a rather arboreal species.

The shell of this species reaches about 0,7 cm in diameter.

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The individuals from Savai’i and Ta’u are taller than those from the other islands, and thus were originally described as a distinct form (var. usurpata (Mousson)).

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References:

[1] H. Burrington Baker: Zonitid Snails from Pacific Islands – Part 1.1. Southern genera of Microcystinae. Bernice P. Bishop Museum Bulletin 158: 1-102. 1938
[2] Robert Cowie; Rebecca J. Rundell; Falaniko Mika; Pasia Setu: The endangered partulid snail Samoana thurstoni (Cooke and Crampton, 1930) on Olosega and the land snail diversity of the Manu’a Islands, American Samoa. American Malacological Bulletin 17(1/2): 37-43. 2002
[3] Robert H. Cowie; A. C. Robinson: The decline of native Pacific island faunas: changes in status of the land snails of Samoa through the 20th century. Biological Conservation 110: 55-65. 2003

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diastole-schmeltziana-jdc

Depiction from: ‘Albert Mousson: Faune malacologique terrestre et fluviatile des îles Samoa, publiée d’après les envois de M. le Dr E. Graeffe. Journal de Conchyliologie 17: 323-390. 1869’

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Partula callifera Pfeiffer

Callus-carrying Tree-Snail (Partula callifera)

This species was described in the year 1856.

The Callus-carrying Tree-Snail occurred in the higher parts of the Haamoa valley in the east of the island of Ra’iatea, where it formerly was found quite commonly, sitting on the foliage of the native vegetation.

The shells reached a heigth of 1,7 to 2,1 cm.

The species died out for the same reasons as all of the other extinct Polynesian tree-snail species.

Endodonta rugata (Pease)

Wrinkled Disc Snail (Endodonta rugata)

The Wrinkled Disc Snail, which occurred on the island of Maui, was described in the year 1866.

The shells of this species reach a size of about 0,5 cm in diameter.

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References:

[1] Alan Solem: Endodontoid land snails from Pacific Islands (Mollusca: Pulmonata: Sigmurethra). Part I, Family Endodontidae. Field Museum of Natural History Chicago, Illinois 1976

Carelia pilsbryi Sykes

Pilsbry’s Carelia (Carelia pislbryi)

This species was described in the year 1909 on the basis of subfossil shells, which had been found on the Kaakaaniu- and the Kalihikai beaches on the island of Kaua’i.

The shells reached a height of up to 8,5 cm.

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Pilsby’s Carelia obviously inhabited lowland regions, and thus was one of the first species that felt victim to the Polynesian Rats (Rattus exulans (Peale)), which had been introduced by the Polynesian settlers.

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Another subspecies, the Tsunami Carelia (Carelia pilsbryi ssp. tsunami Cooke & Kondo), was described in the year 1952 from numerous subfossil shells, which had been uncovered at April 1, 1946 by far-ranging tidal waves on the Lepeuli beach on the island of Kaua’i, but of which, however, not a single one was intact.

This form differs from the nominate race, among other things, by its more compact embryonic whorls, and by its spiral striation pattern.

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References:

[1] C. Montague Cooke, Jr.; Yoshio Kondo: New fossil forms of Carelia and Partulina (Pulmonata) from Hawaiian Islands. Bishop Museum Occasional Papers 20(20): 329-346. 1952

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carelia-p-pilsbryi-mc

nominate race

Depiction from: ‘G. W. Tryon; H. A. Pilsbry: Manual of Conchology. Second series: Pulmonata. Vol 21: Achatinellidae (Amastrinae) 1911’

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